PROBLEM $3$: $(20$ points$)$

Part A:

$[15$ points$]$

A vertical piston$-$cylinder device initially contains $0\mathrm{.}2m^3$ of air at $300$ kPa and $22C.$ A valve connected to the cylinder is now opened, and air is allowed to escape at constant pressure and temperature until the volume of the cylinder goes down by half. Assuming air to be an ideal gas with variable specific heats. Determine the following:

Mass of air that left the cylinder, in kg

$[6$ points$]$

Boundary work during this process, in kJ

$[2$ points$]$

Heat transferred during the process, in kJ $.$

$[7$ points$]$